1. Field of the Invention
This invention generally relates to the field of baking accessories, and more particularly to a baking sheet with a slide-off ramp suitable for baking and/or heating certain baked goods such as pizzas.
2. Description of the Prior Art
The most popular type of non-stick pans have a uniform or continuous substantially vertical wall that extends about the entire peripheries of the pans. These are available as a deep loaf, a shallow jellyroll pan (when a shallow sheet has four sides it is called a jellyroll pan) and intermediate round pans. Non-stick is popular because it is low-cost and easy to use and clean. The coating is either silicone-based or PTFE-based, and is applied to carbon steel or aluminized steel. All of these shapes have a rolled edge. A rolled edge can only be applied to metal that lies in the same plane, therefore a plane could be placed along the top of all of the pieces above and it would touch the entire rolled edge. Non-stick bakeware needs less greasing than uncoated bakeware, a selling point to the consumer. The disadvantages of non-stick are that unless it is of the PTFE type, it will degrade in the dishwasher, and all types of non-stick will scar when they are exposed to sharp objects such as a cutting knife.
The rolled edge gives several advantages:                1. A non-stick coating is less likely to chip away because the sides are rounded.        2. The rolled edge is easier to hold and clean.        3. The rolled edge provides a point at which the pan can be hung during the time the non-stick is sprayed on manufacturing.        
Other bakeware is known. Professional bakers prefer to cook on raw aluminum pans. The aluminum transfers heat well and is very durable. However, aluminum pans must always be greased well. It is not necessary to roll the edge because these pans are not coated and professionals are not concerned about the raw edge.
Fancy stainless steel bakeware has been sold mainly on the basis of its lustrous appearance. This bakeware will uphold a better finish than raw aluminum, but it does not transfer heat as well (which is important so that one can cook evenly) and it also needs to be well greased.
Tinned steel bakeware is usually the least expensive type of bakeware available, but it is also the least durable.
All of these types of bakeware without non-stick coatings need lengthy cleanups after use.
The standard four-sided, non-stick type of jellyroll pan on the market has four sides. Therefore, to remove the cookies one must lift them off the sheet rather than slide them over the edge. This can break or otherwise damage the cookies while they are still hot and soft.
Also known is a non-stick insulated cookie sheet. The advantage of an insulated sheet is that it heats more gently, and thus the cookies cook before they brown on the bottom. When insulated cookie sheets were first introduced, they tended to be made of aluminum or of tinned steel and so had longer cooking times. Now with dark-colored non-stick insulated sheets, the darker color makes the cooking time closer to normal.
Insulated sheets are typically not dishwasher safe due to the possibility that water may seep in and collect between the sheets. One example of an insulated cookie sheet includes two formed sheets of metal that have been crimped together. Because the edges have a continuous crimp around the perimeter, there can be a folded side only on one or two edges. This is because a fold in sheet metal manufacture can only occur in a straight line.
In some instances an insulated sheet is provided with two folded sides. In this case, there is still a possibility that cookies might slide off the wrong edge. Another insulated cookie sheet, with a fold on two sides, plus a third side with a raw edge has the advantage that here the cookies can be slid off one side only. The drawback, however, is that the third side has sharp edges and may be difficult to clean at the corners. This may be a reason why manufacturers do not use a non-stick coating on this item.
At times it is desired to bake and/or heat certain items that have a pre-baked crust that, unlike fresh dough, does not have a tendency to flow or be viscous. For example, at least partially baked frozen pizzas and/or pies have such a crust. Yet, these items may be frozen and require some baking and heating. However, because they have been frozen ice and/or ice crystals may form on the surfaces of these products that melts when heated. When placed on a solid cookie pan most of the ice formed on the top of the product melts and evaporates. However, the ice on the bottom or condensation that flows to the bottom from ice melting on the product could end up being trapped between the product and the pan. Such condensation, when not fully evaporated, can make the bottom of the product wet and soggy.